A method of manufacturing a stiffener material

Abstract

The present invention provides a method of manufacturing a stiffener material comprising: providing an uncompressed felt layer comprising a primary fibrous material having a density of between 0.08 g/cm3 and 0.16 g/cm3; passing the felt layer through a double belt press; wherein as the felt layer is passed through the double belt press it is maintained under constant pressure whilst first being heated to within 20° C. of a melting point of the primary fibrous material and is subsequently cooled to below the glass temperature of the primary fibrous material to form a compressed material. A stiffener material manufactured according to the method of the present invention is also provided.

1 . A method of manufacturing a stiffener material comprising:
 providing an uncompressed felt layer comprising a primary fibrous material having a density of between 0.08 g/cm 3  and 0.16 g/cm 3 ;   passing the felt layer through a double belt press; wherein   as the felt layer is passed through the double belt press it is maintained under constant pressure whilst first being heated to within 20° C. of a melting point of the primary fibrous material and is subsequently cooled to below the glass temperature of the primary fibrous material to form a compressed material.   
     
     
         2 . A method according to  claim 1 , wherein the primary fibrous material is polyester. 
     
     
         3 . A method according to  claim 2 , wherein the felt layer consists solely of the primary fibrous material. 
     
     
         4 . A method according to  claim 1 , wherein the felt layer comprises a second fibrous material having a lower melting point than the primary fibrous material. 
     
     
         5 . A method according to  claim 1 , wherein the compressed material is coated with a powder adhesive on one or both sides and the compressed material is then passed through a heated double belt press. 
     
     
         6 . A method according to  claim 5 , wherein the compressed material is coated with a powder adhesive on both sides and the compressed material is then passed through a heated double belt press. 
     
     
         7 . A method according to  claim 5 , wherein the compressed material is coated with a powder adhesive on a first side and the compressed material is then passed through a heated double belt press;
 then the compressed material is coated with a powder adhesive on a second side, opposing the first side, and the compressed material is then passed through a heated double belt press.   
     
     
         8 . A method according to  claim 5 , wherein the heated double belt press is operated at a temperature of less than 150 C and a pressure of less than 20 N/cm 2 . 
     
     
         9 . A method according to  claim 1 , wherein the uncompressed felt material is coated with a powder adhesive on one or both sides before the uncompressed felt material is passed through the heated double belt press. 
     
     
         10 . A method according to  claim 9 , wherein the uncompressed felt material is coated with a powder adhesive on both sides before the uncompressed felt material is passed through the heated double belt press. 
     
     
         11 . A method according to  claim 9 , wherein the uncompressed felt material is coated with a powder adhesive on a first side before the uncompressed felt material is passed through the heated double belt press;
 and then the compressed material is coated with a powder adhesive on a second side, opposing the first side, and is then passed through a heated double belt press.   
     
     
         12 . A method according to  claim 5 , wherein the powder adhesive is one or more of polycaprolactone, ethylene vinyl acetate, polyurethane, polyester, or polyamide powder. 
     
     
         13 . A method according to  claim 1 , wherein the uncompressed felt layer is heated to the melting point of the primary fibrous material as it is passed through the double-belt press. 
     
     
         14 . A method according to  claim 1 , wherein the thickness of the compressed material is between 0.5 mm and 2.5 mm. 
     
     
         15 . A method according to  claim 1 , wherein the density of the compressed material is between 0.4 g/cm 3  and 1.1 g/cm 3 . 
     
     
         16 . A method according to  claim 1 , further comprising the subsequent step of forming a laminate material comprising two or more layers of the compressed material. 
     
     
         17 . A method according to  claim 16 , wherein the laminate material is formed by passing the layers through a heated double belt-press. 
     
     
         18 . A method according to  claim 1 , further comprising the subsequent step of forming a sandwich material comprising two layers of the compressed material having a filler material between the two layers of the compressed material. 
     
     
         19 . A method according to  claim 18 , wherein the sandwich material is formed by passing the layers of compressed material and the filler material through a heated double belt press. 
     
     
         20 . A method according to  claim 17 , wherein the laminate material or the sandwich material is coated on at least one side before being passed through the heated double belt-press. 
     
     
         21 . A method according to  claim 20 , wherein the laminate material or sandwich material is coated on both sides before being passed through the double belt press. 
     
     
         22 . A method according to  claim 20 , wherein the laminate material or sandwich material is coated on a first side before being passed through the heated double belt press. 
     
     
         23 . A method according to  claim 22 , wherein the laminate material or sandwich material is subsequently coated on a second side, opposing the first side, and is then passed through a heated double pres. 
     
     
         24 . A method according to  claim 16 , wherein subsequent to forming the laminate material or sandwich material the material is coated on one or both sides and passed through a heated double belt press. 
     
     
         25 . A stiffener material made according to the method of  claim 1 .